Deoxyribonucleic acid (DNA) is a molecule that encodes the genetic information of living organisms. A naturally-occurring double-stranded DNA includes a linked chain of alternating deoxyribose sugars and phosphate groups as a backbone for four nucleotide bases, e.g., including adenine (A), cytosine (C), guanine (G), thymine (T), which are attached to the deoxyribose sugar. The genetic information of DNA is encoded as a sequence of these nucleotide bases. The four nitrogen bases can form hydrogen bonds that hold two individual strands of the DNA together. For example, in naturally-occurring double-stranded DNA, adenine bonds to thymine (A=T) and cytosine bonds to guanine (C≡G). The A=T and C≡G bonds are two different types of hydrogen bonds formed by the base pairs. Adenine forms two hydrogen bonds with thymine (A=T) and cytosine forms three hydrogen bonds with guanine (C≡G). For example, the energy of formation of N—H . . . O bonds is approximately 8 kJ/mol, and the energy of formation of N—H . . . N bonds is approximately 13 kJ/mol (e.g., where the dotted line represents the hydrogen bond).
Polymerase chain reaction (PCR) is a widely used method for in vitro DNA amplification. PCR is commonly used in molecular biology to make copies of a particular region of DNA starting from a few copies up to several orders of magnitude. It involves a series of cycles involving different temperature points to facilitate DNA melting and enzymatic replication. However, using thermocycling to facilitate DNA melting and enzymatic replication (e.g., switching between double- and single-stranded DNA) is not necessarily desirable. Heating and cooling can limit device design, and thermocycling can be a power-hungry process.